Cylindrical-grinding machine



Nov. 24, 1925.

C. H. NORTON CYLINDRIGAL GRINDING MACHINE Original Filed Jan. 29, 1921 2Sheets-Sheet 1 as a3 a gharles H. NorTon Nov. 24, 1925.

C. H. NORTON CYLINDRICAL GRINDING MACHINE Original Filed Jan. 29, 1921 2Sheets-Sheet 2 Charles H. NorTon for the grindin of such articles as thePatented Nov. 24, 1925.

UNITED STATES CHARLES H; NORTON, orrnamvnnn, cormnc'rrcur,

ASBIGNOR '10. NORTON COI- ?ANY, OF WORCESTER, MASSACHUSETTS, ACORPORATION OF MASSACHUSETTS.-

CYLINDEICAL-GRINDING MACHINE.

Application filed January 29, 1921, Serial No. 441,047; Renewed October18, 1924.

To all whom it may concern:

Be it known that'I, CHARLES 'H. N ORTON, a citizen of the United Statesof America, residing at Plainville in the county of Hartford and Stateof Connecticut, have invented certain new and useful Improvements inCylindrical-Grinding Machines, of which the following is a -full, clear,and exact specification.

My invention relates to a machine for grinding cylindrical objects andmore par.- ticularly to a double head machine having drivenwork-supporting spindles adapted PIIIS and bearin s o crankshafts. 1

The finisliing of crankshaft pins and bearings, because of the highdegree of accuracy and finish demanded, is now usually done on agrinding machine. In order to avoid torsional strains in the work duringthe grinding operation, it is advisable to drive the workv positivelyfrom both ends,. instead of having it driven from one end alone as ingrindin straight cylindrical pieces. en grin ing the pins ofcrankshafts, it becomes necessary tosupport the shaft ec-.' centricallyof the axis of rotation of the driving spindles in special holdingdevices, this eccentricity varying with the throw of the crank. It isalso highly important that f the work be held rigidly and that the axesand maintained in such alignment aligned or a long eriod of time, sothat, whenthe work is finls hed, the axes of the pins will be parallelfor pins angularly disposed relative to each other or in alignment forpins on the same of the drivingspindles be accuratelfy side'of theshaft. It will be apparent that a machine having a any sli ht deviationfrom accurate alignment 0 the axes of the work driving spine preciselysynchronized drive for said spindles will result in imperfections in thework. Since the permissible error in this kind of work is very small,the elimination of such factors becomes highly important.

It is therefore one object of my invention to overcome thesedifliculties by roviding massive wor -holding table of ri idconstruction in which the spindles of t e work heads are supported onbearing surfaces rigid with the table so that their axes are alignedwith each other and steadily held in such aligned relation, andarrangcdin parallelism with the table through the left-han ways, wherebytables of may be readily intercha grinding operations. To t is end Iprovide a table having work head members rigid and integral with thetable,.said members having aligning surfaces, which may be andpreferably are V-shaped in cross section, ada ted different lengths edfor different to receive bearing blocks having sur aces or adjustingthem with relation to the spindle.

- It is a further object of my invention to provide eflicient andpositive driving connections from a shaft on the base of the machine tothe two spindles in the work heads, whereby the balance of the s indlesis assured and they are driven synchronously, providing an even wear ofthe bearings and the elimination of torsional strain in the work duringthe grinding operation.

It is a still further object of my invention to rovide an oiling systemin connection wit my spindle bearings that is highly ef ficient inoperation and assures an even distribution and a constant sup 1y of.oilbetween the spindle and its cy indrical bearing member.

lVith these and other objects in view, as will appear from the followingdisclosure, my invention resides in the combination of parts set forthin the specification and covered by the claims appended thereto.

In the drawings in which like reference numerals indicate likeparts:

- Figure 1 is a front elevation of a grinding machine embodying myimprovements, parts being shown in section or broken away to show thedriving connections to the work heads;

' Fig. 2 is an enlar ed transverse section (f work head, the table, anda part of the base;

Fig. 3 is an enlarged vertical section through the work head and part'ofthe driving connection thereto, a part of the spindle and its bearingblock being shown in elevation;

Fig. 4 is a partial section through the gear the spindles the worktable, showing the integral work head members;

Fig. -7 is an enlarged perspective view showing a lower bearing blockand its opposed adjustable blocks; and

Fig. 8 is a sectional view similar to Fig. 2

showing a modification of the spindle bear- In the embodiment of myinvention selected for illustration, I have shown a slide, such as thework table 10, having parallel ways 11 mounted to slide on the parallelways 12 of any suitable form of base 13, said slide or table beingprovided with means for moving it on the ways, such as the usual rack 14attached to the under side of the table and meshing with a pinion 15 ona transverse shaft 16 driven as from the hand wheel 17 throughintermediate gearing 18. In Fig. l I have shown the grinding wheel IV,which is mounted on a cross slide in the usual way, in operativerelation to the work X.

The table 10, which has a massive rigid construction, as will beapparent from an inspection of Fig. 6, is provided at its ends withrigidly and integrally formed worksupporting members 19 having surfaces20 for receiving the bearing blocks 21, said surfaces being made invaccurate axial alignment with each other, as by planing and scraping theparts, and'arranged in parallelism with the table Ways. These alignedsurfaces thus form reference surfaces, both initially and after theoriginal bearing blocks become worn so as to require replacement, foraccurately aligning the partial cylindrical surfaces 23 of said blocksand hence the axes of spindles 24 which are received in said blocks. Thesurfaces 20 are preferably V-surfaces, as shown, the angle formed by theV being substantially a right angle. The V-shaped aligning surfaces arecut away in intermediate portions, as at the points 25 and 26, to lessenthe cost of scrap mg, it being noted that various shapes equivalent tothat shown in the drawing may be known as V-shaped. Thebearing blocks 21having on their upper sides the partial cylindrical surfaces 23 toreceive the spindles are formed on their under sides with V-surfaces 27mating the V-surfaces 20, so as to accurately fit the same. By grindingor planing these blocks in pairs on an arbor, the V-surfaces 27 can bemade to contact with the V-surfaces 20 at all points not cut away, andthe axes of the surfaces 23 will be accurately aligned, thus assuringthe similar alignment of the work spindles 24. The blocks may be drawntightly against the V-surfaces 20 by means of screws 30 (Fig. 2).

To hold the s indles in correct relation with the lower aring blocks 21and to prevent jumping or vibrating, I may employ any suitable means,but I have shown a pair of upper bearing blocks 31 for each lower block,one of said upper blocks bein arranged adjacent each end of the spindle.The upper sides of the spindles are enclosed in partial. cylindricalcasings or caps 32 which are fastened to the work head membersintegrally formed with the table 10 by the screw bolts 33. The bearingblocks 31 are located between these casings and the spindles and may beadjusted toward the spindles by means of screw bolts 34 provided withknurled heads 35 and the usual lock nuts 36. These screwbolts 34 formpreci sion means for adjusting the bearin blocks and their knurled headsare of sue a size that the operator cannot manuall set the bearingblocks against the spin les with sufficient pressure to crush out theoil film.

It is highly important in grinding the pins of crankshafts, for example,that the work holders be accurately aligned when the work is clampedthereto to prevent any twisting or distortion of the shaft which wouldresult in imperfections in the finished work, and for a like reason itis important that the two work-drivin spindles be driven in precisesynchronlsm. I obtain such a drive by mounting a gear 37 on the outerend'of each spindle 24 and driving these ears by any suitable means suchas from t e shaft 38 which is mounted adjacent its ends in bearingbrackets 41 connected to the table as by screws 42. To make the machineself-contained, this shaft is preferably driven through a gear 43arranged between its ends, said gear being splined the eto to allowrelative sliding movement etween it and the shaft, the shaft beingsupported on opposite sides of this gear by a suitable bearing bracket39 connected to the base. The drive shaft 44 mounted in the base of themachine (see Fig. 1) is in turn driven by any suitable means such asdrivin connections from a motor (not shown? on the back of the machine.These gearsare preferably sprocket gears driven by chains. The shaft 38on the table is driven from a sprocket gear 45 on shaft 44 in the baseby means of a chain 46 and the Hill shaft 38 drives through sprocketgears 47 j dies 24 and the sprocket substantiall cup-shape rotationbetween the formed with a reduced squared head to receive a wrench orother tool for rotating it, and, inwardly of this s uared head, it isformed with a screw three to receive a nut 58 thereon for drawing thebracket and cap in close frictionalcontact, whereby the idler will beheld in adjusted position.

The spindles are provided at their inner ends with the usual plates(SO-for fastening the work holders 61 to which the work X is clamped inthe usual manner. To secure a fine rotary adjustment-between thespinears 3'] for precisely aligning the work 0 amping means, I may mountat least-one of the sprockets 37 in the manner shown in Fi s. 3 and 4.have there shown the s roe et 37 as being to fit over the end of thespin le and connected thereto by bolts 62. The bolts extend througharcuate slots 63 in the sprocket to allow limited relative sprocket and.the spindle. -O n-diametrically opposed sides of the sprocket '-I rovideenlarged openings 64 having bevelled sides. openings receive screw bolts65 which screw into the ends of the spindle and have bevelledportions'fitl'thereon for cooperation with the bevelled sides of ;theopenings 64. These bolts are both arranged at one side of a verticallane assii g through the axis of the 'upperbolt the sprocket is rotatedby the spind e, wh e the centers of the openings 64 are arranged in thislane and bothbolts are normally screwed}, own until their bevels engagethe bevelsiofthe openings. Then it iscsiredto adjust the sprocket on theshaft, let us say in a clockwise direction, Fig. 4, the bolts 62 areloosened and the lower bolt 65 is likewise unscrewed. so as to back offits bevelled surface from the bevelled surface.

in the opening 64, and by tightening the c agement of the bevelledsurfaces on the hot and its cooperating opening. until the bevelledsurfaceson the. lower bolt and its cooperatingopening1 are again in engaement. To take up t e end thrust, I provide the spindles 24'w1th collarsengaging the bearing blocks 21'at oneiend thereof and nuts 71 held inplacetby suitable locknuts 72 at the opposite ends. 4 1

Another feature of my invention fcomprises an eflicient oiling systemwhich in sures a copious supply of oil between the spindles and theirhearing bushings. This may comprise an oil well 73 arranged atsubstantiall the central portion of the work headbc ow the work spindleand o cmng upward into the spindlebearings. prcfcrably convey the oil.out of this well by means of a chain 74 passing through slots 75 in thebearing blocks and around the spindles. Channels are rovided in theupper edges of the bearing locks 21, these channels iaving their bottomsslopingaway from the slots 75 to the ends of the bushingsv and towardsthe spindle so that as the oil is carried by the chain in therevolutionoi'the s indie to the top of the spindle, some of it ows intothese channels and along them in contact with the spindle, any sur lu soil findingits way to the ends of the bushing where it drops by gravityor'is thrown off by centrifugal force from the collars and the nuts 71and 72 and. is caught by. the oil uards 76 and 77, from whence it isreturned y gravity through the sloping channels 78 and 79 to the well73. v

An advantageous feature of my invention relates to theinterchangeability of work tables. This is of considerable importancefrom the point of view of the user of such 7 a machine having severaldiflerent lengths of crankshafts to grind and yet not having sufficientof such work to warrant having two machines. The ways of the tables andthe base being scraped to standard bars, it'- willbe obvious thatdifferent tables will fit the same base and a user of this machine willbe enabled to grind different lengths of. work if equipped with a singlemachine having interchangeable tables of different. lengths. For smalldifferences in the lengths of the crankshafts, say several inches, itmay be unnecessary to use different sized tables such accommodationbeing obtained by substituting different work holders. Where .the

difference in length is greater, this method of adjusting the machinetothe work would i I 10:)

not be as desirable as the interchangeable tables.

In Fig. 8,-I have shown a modified construction of the spindle bearingsshown in.

Figs. 2 and 3, whichmay be advantageously employed in certain grindingoperations, because it permits of a very line lateral pollO sitioning ofthe spindle in its bearings. I I there employ adjacent each end of aspindle two upper bearing blocks 81 similar to the 85, similar to thecaps 32, except as shown modifiedin Fig. 8, to adapt it to receive twoupper bearing blocks. M oiling system insures a copious supplyo oil tothe. spindle and bearings, so that, during the normal operation of themachine, there always exists a thin film of oil between the spindle andthe hearings in which it rests, which is only a fraction of a thousandthof an inch in thickness. Because of this fact, I am enabled to bringgreater pressure to bear on the upper bearing blocks 81 arranged on oneside of the spindle than on those arranged on the opposite side by aproper manipulation of the adjusting screws 82, and thus move thespindle in the direction of the greater thrust a fraction of athousandth of an inch'by forcin out some of the oil film between it andtie bearing block 21 on that side of the spindle opposite the sidereceiving the greater thrust.

It is obvious that changes may be made in the specific construction ofmy device and that equivalent elements may be substituted for the artsherein disclosed without departing romthe scope of my invention as exressed in the claims appended hereto.

aving thus described my invention, what I claimas new and desiretosecure by Letters Patent is:

1. A double head grinding machine comprising a base having parallel waysthereon, a 'slidable work table having ways mating with the base ways,work head members integral with said table, spindle bearings thereonhaving bearing surfaces in precise axial alignment, and work-supportingspindles mounted on said surfaces and aligned thereby.

2. A double. head grinding machine comprising a base having parallelways thereon, a work table slidably mounted on said ways, integral workhead members on opposite ends of said table, lower spindle bearingsthereon having cylindrical surfaces in accurate axial alignment,work-supporting spindles mounted on said surfaces and aligned thereb andfine precision means to hold the spind es in correct relation with thelower bearing surfaces.

3. A grinding machine comprising a base having parallel ways thereon, aslide [HOV-81'. bly mounted on said ways, spindle suppor ing membersintegral with the slide and hav-. ing aligning V-surfacesand bearingblocks having V-surfaces mating with said aligning surfaces and rigidlyfixed thereon, said blocks having spindle bearing surfaces axiallyparallel with said aligned surfaces of .the slide.

4. A grinding machine comprising a base having parallel ways thereon. awork table slidably mounted on said ways, a work head member integralwith said table and having a V-surface arranged in arallelism with thetable ways, a bearing b oek having a V- surface matin with the V-surfaceon said member, said aring block having a cylindrical bearin surfaceaxially parallel with and on the si e opposite the V-surface theresaidcylindrical bearing surface and adjustable means for holding saidspindle in correct relation with said bearing block.

5. A double head grinding machine comprising a base having parallel waysthereon, a slidable work table having ways mating with the base ways,work head members integral with the table and having aligning V-surfacesparallel to the table ways, work supporting s indle blocks having lowerV- surfaces mating with said aligning surfaces and upper cylindricalsurfaces for the spindles, said blocks being rigidly mounted on saidmembers, whereby the spindle axes traverse in a stralght line.

6. A double head grinding machine comprising a base having parallel waysthereon, a work table slidably mounted on said ways,

lower bearing members rigidly fixed on said 7 table in axial alignmentand spaced relationship, spindles mounted in said bearings," supportingmembers rigidly fixed to said table and extending above said spindles,upper floating bearing blocks engaging said spindles, and meanscooperating with said supporting members to position said floatingbearing blocks accurately with relation to the spindles.

7. A double head grinding machine comprising a base having parallel waysthereon, a work table slidably mounted on said ways and havingwork-supporting portions on its ends provided with V-shaped aligningsurfaces, lower spindle bearing blocks having V-shaped surfacesmating'with said aligned surfaces and rigidly mounted on said tableportions, said bearing blocks having cylindrical surfaces in axialalignment, spindles mounted therein, and upper adjustable hearing blocksmounted on the table for engagement with the spindles to hold the samefirmly against the cylindrical surfaces.

8. A double head grinding machine comprising a base having a Vway and anas soeiated way parallel thereto, a work table having ways on its undersurface mating the ways on said base, said table having align.- ingV-surfaces ad'acent its opposite ends arallel with sai V-way, lowerbearing locks havin V-surfaces mating with the V-surfaces o the table,said blocks being rigidly fastened .to said table, each block having anupper cylindrical surface, the axis of which is parallel with thelower-V-surfaces of the blocks, spindles mounted in said bearing blocksin axial alignment, a casing mounted over said spindles, adjustableupper bearing blocks mounted in said casing and means cooperating withsaid blocks and casing to hold the upper blocks in accurate contact withthe spindles.

9. A grinding machine comprising a slidable work table,'work headsintegral with said table,

Ill)

spindles.

10. A grinding machine comprising a base, ways on said base, a worktable slidably mounted on saidways, rigid work heads arranged adjacentthe ends of said table, bearing surfaces in fixed axial alignment onsaid work heads, work-driving spin dles supported in said bearings, ashaft mounted on said slidable work table, chain driving.connectionsbetween said-shaft andthe work-driving spindles, a fixed drive shaft inthe base of the "machine, and chain and the movable shaft.

11. A grinding machine comprising a base having ways, a slidable worktable having ways mating the ways on the base, a spin,

dle bearing block -rigidly fixed on said table,

and axially parallel with the table ways, a work-supporting spindlemounted on said bearingblock, driving means for said spindle arrangedadjacent one endthereof and exerting a downward pull on the spindle, and.a relatively massive work holder at the other end thereof, the pullexerted by said driving means and the weight of the work holder and worksubstantially balancing each other, whereby the bearing block will beevenly worn. I

12, A grinding machine com rising a base having ways, a work table sidable on said ways, work supporting heads integral with the table,V-shaped surfaces on the heads in precise alignment, lower bearingmembers having V-shaped surfaces mating with said surfaces on the'heads,rigid connections between the heads and members, partial cylindricalsurfaces on said members, spindles mounted on said members in fixedaxial. alignment and upper adjustable hearing blocks to hold thespindles in position relative to the members.

13. A grinding machine comprising a base havingstandard parallel ways, asliding work table forming one of a set which hasways mating with thestandard base ways, work head members integral with said table, andwork-supporting spindles mounted on said members in fixed axialalignment, whereby the table selected serves as a for supporting work ofthe particular size being treated. 14. A grinding machine comprising abase, ways on said base, a work table slidably mounted on said baseways, work head members integral with and arranged adjacent the oppositeends of said table, lower spindle-supporting blocks thereon havingcylindrical bearing surfaces normally in axial alignment,work-support1ng spindles mounted on said surfaces, and means comprisingfinely adjustable bearing blocks to old the spindles in proper relationswith the supporting blocks and in precise alignment. J

1 5. A grinding machine comprising a base having ways, a work tableslidably mounted on said ways, work head members rigid with said table,lower spindle-supporting blocks carried bysaid members and havingcylindrical bearing surfaces, work drivingand supporting spindlesmounted on said surfaces, and means comprising finely ustablebearingblocks arranged on opposite sides of a plane passingapproximately tliroughtlie spindle axes to. position and the supportingblocks ant in precise alignment.

16. A grinding machine comprising a .holdthe spindles in pro. errelations with" (ll'lVIIlg connections between said fixed shaft basel1aving' parallel ways thereon, a work table slidably mounted on saidways, a work head member on said table which has a V surface arranged inparallelism with the table ways, a bearing block having a V surfacemating with the V surface on said, member, and a work supporting spindlemounted on said block. v

' '17. A grinding machine comprising a base having parallel waysthereon, a work table slidablymounted on said ways, a work head memberintegral with said table which has an upper V surface parallel with thetable ways, a bearing block having a lower surface mating with said Vsurface and means for holding a work supporting spindlewon said block.

18. A grinding machine comprising a base havin parallel ways thereon, awork table slidab y mounted on said ways, a work head member integralwith said table, a bearing block thereon, saidmember and bearing blockhaving interfittingaligning surfaces arallel with said table ways, sa1dbearing llloek havin a cylindrical bearing surface axially para lel withsaid aligning surfaces, and a work supportingspindle mounted on saidblock.

19. A grinding machine comprising a base, a work table on said base, two.work

vheads mounted thereon, workdriving spindles mounted on said heads inaxial ahgn-- I menti'a driving. shaft parallel. with said s m s aft toeach of the spindles, and means to synchronize the spindles.

20. A grinding machine comprising a base, a work table slidably mountedon said base, two work heads mounted thereon, work driving spindlesmounted on said heads'in axial aligmnent, a driving shaft parallelwithsaid s indies and driving connections from said s aft to each of thespindles, a driving member on each spindle, means 0on necting said shaftwith each member to roles and driving connections from said spindles,driving connections between'said aft and ears, and means to rotativelyadjust one 0 said gears relative to the spindle to synchronize said workholders.

22. A grinding machine comprising a base, a work table slidably mountedon said base, two work heads mounted thereon, work driving spindlesmounted on said heads in axial alignment, offset work holders on saidspindles, a driving shaft parallel with said spindles, a gear mounted oneach of said s indles, driving connections between said s aft and gears,means comprising screws having conical portions cooperating with conicalapertures in one of said gears to rotatively ad'ust said lgear relativeto the spindle to sync ronize t e work holders.

, 23. A grinding machine comprising a support for the work, a work headmember on said support which has a V surface arranged I in parallelismwith the axis of work, a bearing block having a lower V surface matingwith the V surface on said member, and an upper partial cylindricalbearing surface an a work supporting spindle mounted on the upperbearing.

A rinding machine comprising. a support for the work, spindle supportingmembers integral with the support and having aligning V-surfaces andbearing blocks having V-surfaces mating with said aligning surfaces andrigidly fixed thereon, said blocks having s indle bearing surfacesaxially parallel w1th said aligned surfaces of the spindle supportingmembers.

Signed at WVorcester, Massachusetts, this 28th day of J an., 1921.

' CHARLES H. NORTON.

